Nearly six years after the disappearance in Iran of private investigator Robert Levinson, and two years after his family received an anonymous email confirming that the former FBI agent was still alive, five photographs taken by Levinson's captors have been released. "I am here in Guantanamo," reads a sign Levinson is holding in one photo. "Do you know where it is?"

According to U.S. investigators who spoke with crackerjack AP reporters Matt Apuzzo and Adam Goldman, yes they do: Levinson is probably in an Iranian secret prison.

Two years later, with the investigation stalled, the consensus now among some U.S. officials involved in the case is that despite years of denials, Iran's intelligence service was almost certainly behind the 54-second video and five photographs of Levinson that were emailed anonymously to his family. The tradecraft used to send those items was too good, indicating professional spies were behind them, the officials said, speaking on the condition of anonymity because they weren't authorized to talk publicly. While everything dealing with Iran is murky, their conclusion is based on the U.S. government's best intelligence analysis.

Levinson's family released the photos to the AP now because his wife believes that the government could be doing more to find her husband, who disappeared in 2007 while investigating cigarette smuggling on Kish, an Iranian island. Iranians have publicly denied holding Levinson, and claimed to have conducted raids in an effort to find him, but the U.S. believes the raids were simply "a ruse by Iranian counterintelligence to learn how U.S. intelligence agencies work."